A newly identified NES sequence present in spastin regulates its subcellular localization and microtubule severing activity.

Spastin, a microtubule-severing AAA ATPase, regulates microtubule dynamics and plays important roles in cell division and neurogenesis. Mutations in the spastin-coding gene SPAST lead to neurodegenerative disorders and cause spastic paraplegia type 4. Spastin has two main isoforms, M1 and M87, that differ only in the presence or absence of 86 N-terminal amino acids and have alternative splicing variants that lack exon4.

A homozygous mutation of C12orf65 causes spastic paraplegia with optic atrophy and neuropathy (SPG55).

Background: Autosomal recessive hereditary spastic paraplegias (AR-HSP) constitute a heterogeneous group of neurodegenerative diseases involving pyramidal tracts dysfunction. The genes responsible for many types of AR-HSPs remain unknown. We attempted to identify the gene responsible for AR-HSP with optic atrophy and neuropathy.

Middle cerebellar peduncles and Pontine T2 hypointensities in ARSACS.

Background And Purpose: Magnetic resonance imaging (MRI) of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) cases in Quebec and Europe was reported to show linear hypointensities in T2-weighted and Fluid Attenuated Inversion Recovery (FLAIR) images of the pons. We attempted to clarify the characteristics of the brain MRI findings in ARSACS cases.

Methods: Eight Japanese early-onset ataxia patients with ARSACS confirmed molecularly were investigated.

A novel adult case of juvenile-onset Alexander disease: complete remission of neurological symptoms for over 12 years, despite insidiously progressive cervicomedullary atrophy.

We present here a 25-year-old woman with genetically confirmed (p.R276L mutation in the GFAP gene) juvenile-onset AxD. Episodic vomiting appeared at age nine, causing anorexia and insufficient growth.

NF-κB mediates aberrant activation of HIF-1 in malignant lymphoma.

Objective: The goal of this study was to explore the molecular mechanisms of aberrant hypoxia inducible factor-1 (HIF-1) activation in lymphoma cells.

Materials And Methods: We analyzed the expression of the α subunit of HIF-1 in three lymphoma cell lines and in normal CD19-positive B cells by Western blotting. To investigate the role of nuclear factor (NF)-κB in abnormal HIF-1α expression in lymphoma cells, we performed a reporter assay using HIF-1α promoter constructs that contained or lacked an NF-κB binding site.

Adult-onset Alexander disease with typical "tadpole" brainstem atrophy and unusual bilateral basal ganglia involvement: a case report and review of the literature.

Background: Alexander disease (ALX) is a rare neurological disorder characterized by white matter degeneration and cytoplasmic inclusions in astrocytes called Rosenthal fibers, labeled by antibodies against glial fibrillary acidic protein (GFAP). Three subtypes are distinguished according to age at onset: infantile (under age 2), juvenile (age 2 to 12) and adult (over age 12). Following the identification of heterozygous mutations in GFAP that cause this disease, cases of adult-onset ALX have been increasingly reported.

FOXO3A as a key molecule for all-trans retinoic acid-induced granulocytic differentiation and apoptosis in acute promyelocytic leukemia.

All-trans retinoic acid (ATRA) induces granulocytic differentiation and apoptosis in acute promyelocytic leukemia (APL) cells, although the detailed mechanisms are not fully understood. We investigated ATRA-induced cellular responses mediated by the transcription factor FOXO3A in APL cells. FOXO3A was constitutively phosphorylated and localized in the cytoplasm in both APL-derived NB4 cells and primary APL cells.

Inhibition of hypoxia-inducible factor-1 function enhances the sensitivity of multiple myeloma cells to melphalan.

Abnormal activation of hypoxia-inducible factor-1 (HIF-1), one of the most important transcription factors for the adaptation of cells to hypoxia, is frequently observed in numerous types of solid tumors. Dysregulation of HIF-1 induces tumor angiogenesis and enhances the expression of anti-apoptotic proteins and glycolysis-associated enzymes in cancer cells, which in turn leads to the promotion of tumor growth. In the present study, we examined the pathophysiologic role of HIF-1 in multiple myeloma.

A novel RUNX1 mutation in familial platelet disorder with propensity to develop myeloid malignancies.

We describe a Japanese family with familial platelet disorder with propensity to develop myeloid malignancies (FPD/MM). Among the three affected individuals, two members developed myeloid malignancies. Sequence studies demonstrate that all affected individuals of the pedigree display a heterozygous single nucleotide deletion in exon 8 of the RUNX1 gene.

An unusual case of a spasticity-lacking phenotype with a novel SACS mutation.

The authors describe an unusual case of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) without leg spasticity, which is a core clinical feature of ARSACS. This is the second family with a spasticity-lacking phenotype in ARSACS. A peripheral nerve conduction study disclosed decreases in motor and sensory nerve conduction velocities with the disease progression.

Identification of GFAP gene mutation in hereditary adult-onset Alexander's disease.

Alexander's disease, a leukodystrophy characterized by Rosenthal fibers (RFs) in the brain, is categorized into three subtypes: infantile, juvenile, and adult. Although most are sporadic, occasional familial Alexander's disease cases have been reported for each subtype. Hereditary adult-onset Alexander's disease shows progressive spastic paresis, bulbar or pseudobulbar palsy, palatal myoclonus symptomatologically, and prominent atrophy of the medulla oblongata and upper spinal cord on magnetic resonance imaging.